Flyswatter (🪰) is “Ping for purge’ing” (IE. gearchcecks with hostile rez-triggers).

Design-wise, ice as dynamic interaction is more fun (IMHO) than ice as just arithmetic breakpoints.

For example, if the Runner doesn't have any viruses installed yet (or only a few virus counters hosted), then even if you would want to end the run, you may let them pass an unrezzed Flyswatter to purge them out later. “Dynamic” non-subroutine abilities include:

• On-Rez (When you rez this ice during a run against this server, …): like Ping, Ablative Barrier, Anemone, even Stavka.

• Trashcans ([trash]: … Use this ability only during a run on this server.): like M.I.C..

For example, how many counters/purgeables in play do you want, to rez it? (Should you just purge two counters off a single Fermenter? How much do you want to keep the Runner out? How likely is it for the Runner to let it cook, install another virus, and re-run that server? It depends.)

Blank Flyswatter (against no Viruses) is much worse than blank Magnet (against no Trojans); you really need the purging to be worth enough credits (given the current metagame / average boardstate). But exactly how many/good Viruses do you need to expect in a Runner's deck, to slot it in? (Out of Jitneki?) IDK. LMK what you think.